Rain-Making Bacteria May Affect Climate

Christner’s team examined precipitation from global locations and demonstrated that the most active ice nuclei – a substrate that enhances the formation of ice – are biological in origin. This is important because the formation of ice in clouds is required for snow and most rainfall. Dust and soot particles can serve as ice nuclei, but biological ice nuclei are capable of catalyzing freezing at much warmer temperatures. If present in clouds, biological ice nuclei may affect the processes that trigger precipitation.

David Sands from Montana State University proposed the concept of ‘bioprecipitation’ over 25 years ago and few scientists took it seriously.

“The role that biological particles play in atmospheric processes has been largely overlooked. However, we have found biological ice nuclei in precipitation samples from Antarctica to Louisiana – they’re ubiquitous. Our results provide an impetus for atmospheric scientists to start thinking about the role these particles play in precipitation,” said Christner. “This work is truly multi-disciplinary, bridging the disciplines of ecology, microbiology, plant pathology and climatology. It represents a completely new avenue of research and clearly demonstrates that we are just beginning to understand the intricate interplay between the planet’s climate and biosphere.”

People have dreamed of rain-making for a long time; Robert Heinlein thought it might one day become a usable technology in 1941.

Oklahoma and half of Texas were covered with deep, thick clouds. Lazarus was amazed and somehow pleased; it reminded him of other days, when weather was something experienced rather than controlled. Life had lost some flavor, in his opinion, when the weather engineers had learned how to harness the elements...

Then he was down in it and too busy to meditate. In spite of her size the freighter bucked and complained. Whew! Ford must have ordered this little charivari the minute the time was set-and, at that, the integrators must have had a big low-pressure area close at hand to build on.
(Read more about weather integrators)

John Jacob Astor IV thought about the idea in his 1894 work A Journey in other Worlds.

"Rain-making is another subject removed from the uncertainties, and has become an absolute science. We produce clouds by explosions in the atmosphere's heights and by surface air forced by blowers through large pipes up the side of a mountain or natural elevation and there discharged through an opening in the top of a tower built on the highest part. The aeriduct is incased in a poor heat-conductor, so that the air retains its warmth until discharged, when it is cooled by expansion and the surrounding cold air. Condensation takes place and soon serves to start a rain.
(Read more about aeriduct)